Network-attached storage (NAS) is increasingly being used by enterprises to store their data. Scale-out NAS refers to NAS solutions in which the file system may span any number of physical nodes. In general, Scale-out NAS enables file systems that are orders of magnitudes larger than traditional NAS.
However, having such large file systems results in a file system backup operation taking a very long time. In general, this is because current backup techniques, developed for traditional NAS, are inherently sequential in nature and therefore do not scale up for Scale-out NAS environments.